This invention relates to an improved system for providing a photographed subject with selected backgrounds, and more particularly, to a system in which a device is mountable directly to a camera whereby a subject may be photographed with a desired background not requiring the use of painted backdrops, rear projection screens, front projection screens, or the like.
Selection of photographic backgrounds is very important to the photographer, particularly to the commercial portrait photographer who must rely on such backgrounds to make his work consistently interesting and appealing to the eye. Selected photographic techniques have been heretofore used to eliminate or minimize the intrusion of an objectionable background in a photograph. One such technique involves shooting at as wide open a lens aperture as is practicable. In this manner, the depth of field of lens used is minimized and the background will appear to be an indistinguishable blur, when the subject is in focus. Such techniques, however, add nothing to overcome the problem of including an otherwise undistinguishable background as part of the finished pictures.
The use of a painted backdrop is as old as the art of commercial photography itself, to which countless tintypes and daguerretypes will attest. Such backdrops are, of necessity, limited in subject matter, difficult to create and maintain, cumbersome to erect and burdensome to carry. Thus the photographer was fairly restricted to the confines of his own studio, and likewise limited in the number of available backdrops he could offer to his clients.
A more recent innovation has been the use of photographic screens onto which transparencies may be projected to produce a desired background. One such projection technique involves a translucent screen and a slide projector mounted at its rear. The image thus appears on the screen's front surface. With the slide so projected, the subject stands in front of the screen and the photographer proceeds conventionally with his shooting.
While offering a somewhat more portable and flexible backdrop system, the rear projection approach requires erection of a screen, positioning of the projector at a distance behind the screen sufficient to enable the projected image to fill the screen, sources of electrical power to operate the projector, and elaborate and carefully controlled front lighting techniques to illuminate the subject without "washing out" the projected image.
A variation of this technique involves front projecting an image onto a screen through a beam splitter mirror which directs the reflected screen image back to a camera. The subject to be photographed is positioned coaxially with the lens of the camera at a position beyond the beam splitter. Such an apparatus is described in U.S. Pat. No. 3,366,438 issued to H. W. Hartman.
A variation of this procedure may be seen in U.S. Pat. No. 3,920,320 issued to Ellis and Ryan, where the transparency projector, the beam splitting mirror and the camera have been combined on a single chassis.
As is evident from a reading of both patents, a projection screen is still required and care must be taken in lighting and in projecting the image onto the screen to assure that shadows from the subject positioned before the screen will not intrude onto the projected backdrop.
Problems are also encountered in adequately lighting the subject while maintaining the sharpness and clarity of the projected background. It may also be seen that, while the two patents discussed above offer some significant advantages, the portability and ease of use of each described apparatus is somewhat limited due to the cumbersome equipment lighting and projection screen involved.
A somewhat more compact attachment, for causing a grid or other desired reference pattern to be projected onto the film in the camera and also onto the viewing screen of the camera's viewfinder, at the same time that a subject is being photographed by the camera, is disclosed in Faasch U.S. Pat. No. 3,376,800. Faasch discloses a beam splitter mirror for reflecting a transparency image to the camera lens and for allowing the subject to simultaneously be photographed through the beam splitter. We have discovered, however, that when a beam splitter mirror is interposed between the camera lens and a lens for focusing a transparency image, vignetting may occur. We have also discovered a novel system for alleviating such vignetting, by effectively focusing the entrance pupil of the camera lens approximate the exit pupil of the lens which focuses the transparency image.
Therefore, it is an object of the present invention to provide simple apparatus for combining selected film transparencies as backgrounds with subjects to be photographed, with the problem of vignetting being alleviated.
Other objects and advantages of the present invention will become apparent as the description proceeds.